Underground radio communication system for roadways

ABSTRACT

A roadway radio communication system for transmitting radio communication signals to vehicles traveling along a roadway, including airport runways, in which four or more conductor array of communication antennas, parallel oriented longitudinally beneath the road surface and/or ground surface, constitute radiation antenna means, and in which the communication signals are fed to the center and adjacent pairs of wires in out-of-phase relation, and the communication radio signals are applied to the outermost pair of wires in cancelling-phase relation for developing an antenna pattern immediately over the roadway and in which the antenna pattern does not substantially extend over lateral areas beyond the edge of the roadway, and in which the wires constituting the radiation antenna means are of substantial sized conductors measured along their diameter and the conductor is encased in a generally low dielectric constant insulation material of substantial thickness in relation to the diameter of the conductor wire.

United States Patent Thrasher 51 June 27, 1972 I [72] Inventor:

[54] UNDERGROUND RADIO CONIMUNICATION SYSTEM FOR ROADWAYS John Peter Thrasher, Kensington, Md.

[73] Assignee: Peter V. Gureckis, Potomac, Md.

[22] Filed: Oct. 28, 1970 [21] Appl. No.: 86,921

[58] fieldofsearch ..179/82;325/28,101,129,156,

Primary Examiner-Benedict V. Safourek Attorney-Keith Misegades and George R. Douglas, Jr.

[ ABSTRACT A roadway radio communication system for transmitting radio communication signals to vehicles traveling along a roadway, including airport runways, in which four or more conductor array of communication antennas, parallel oriented longitudinally beneath the road surface and/or ground surface, constitute radiation antenna means, and in which the communication signals are fed to the center and adjacent pairs of wires in out-of-phase relation, and the communication radio signals are applied to the outermost pair of wires in cancelling-phase relation for developing an antenna pattern immediately over the roadway and in which the antenna pattern does not substantially extend over lateral areas beyond the edge of the roadway, and in which the wires constituting the radiation an- [56] Rd Cited tenna means are of substantial sized conductors measured UNITED STATES PATENTS along their diameter and the conductor is encased in a generally low dielectric constant insulation material of sub- 2,407,417 9/1946 Halstead ..179/82 stamial thickness in Elation to h diameter f the conductor 2,980,793 4/1961 Daniel ..325/ 178 X wire 3,346,864 10/1967 Harmon ..343/7l9 5 Claims, 1 Drawing Figure 32 PROGRAM F e H H 60 SOURCE i TO NEXT i300 SECTION (ammo) f o K 40 V 38 V I I st 1*) N, i 30 l I l E 3 3 i e s' o w o ,2 .E E

UNDERGROUND RADIO COMMUNICATION SYSTEM FOR ROADWAYS This application is an improvement over Rohrer US. Pat. No. 3,470,474. The invention relates to an improved roadway radio communication system for transmitting radio communication signals to vehicles, such as trucks, cars and airplanes, for traveling along a vehicle roadway, and more particularly the invention relates to a means for constraining the antenna radiation by means of parallel oriented longitudinally arranged conductor wires within the roadway under the surface thereof, the wires being of substantial thickness for improving the conductivity thereof, and in which the insulation means thereof is of substantial thickness and of low dielectric constant or lossy characteristics, and the ends of the'center-fed antenna radiation means are terminated by terminating units.

An object, therefore, of the invention is to provide a low signal in substantial phase opposition to certain of a set of wires in a five-wire radiation antenna system, whereby communication signals of predetermined level are confined to the immediate upper vicinity of the roadway and attenuated to a predetermined level remotely outwardly of the roadway.

Another object of the invention is to provide a set of five road-imbedded wires comprising a substantial sized conductor means measured along its diameter and in which the conductor is encased in a generally low dielectric constant or lossy insulation material also of substantial thickness relative to the diameter of the conductor wire.

A further object of the invention is to provide a set of five road-imbedded wires being disposed in a substantially uniform predetermined depth substantially throughout the length of the wires beneath the surface of the roadway, the five-wire system being center-fed and in which the ends thereof are connected to terminating units.

Another object of the invention is to provide terminating units to end elements of a center-fed underground radio communication system for highways.

The above and other objects and advantages of the invention will become apparent upon full consideration of the following detailed description and accompanying drawings in which the FIGURE relates to a circuit and schematic diagram in top plan form of a portion of a roadway schematically showing the several sections of the underground communication system according to a preferred embodiment of the invention.

Referring now to the drawings, there is shown an un derground radio communication system for roadways (not shown) in which there are a series of five road and ground-imbedded wires l2,l2,l2,12,l2 or A,B1,B2,Cl,C2, arranged generally parallel oriented longitudinally beneath the surface of such roadway.

The depth of the antenna radiation means in the roadway may extend from a very small distance such as a fraction of an inch, up to 12 inches, more or less. The radiation wire means 81,82 are center-coupled to phase amplifiers 14, such that the center wire of the radiation antenna means is center-fed by an out-of-phase amplifier l6 and the outer pair of wires Cl,C2 is center-fed through impedance means 18,18, respectively, from the output of the out-of-phase amplifier 16.

The phased amplifiers 14,14,16 are each fed by a bridging amplifier 22 which receives radio communications from radio communication transmitter means 26 including a modulator unit 28 and an oscillator 30 of conventional and standard construction and operation. A program source 32 for supplying communication signals to the modulator 28 may be disposed in a studio, in which any of several program inputs 36,38,40 may selectively be fed in sequence through the program source 32 to the modulator 28. Thus along the roadway in which the radiation antenna means having the set of imbedded wires A,B1,B2 therein enables one driving a vehicle along the roadway to tune in to the radio signals and communications emanating from the five-wire set of radiation antenna means.

For improving the application of the roadway radio communication system, in addition to the concept of the radiation antenna means constituting a set of five road and ground-imbedded wires A,B1,B2,Cl,C2, there may be provided impendance terminating units 50,52 at the end of each wire. These terminafing units provide for wave terminating of the communication signal of the center-fed radiation antenna means, and by means of the phasing arrangement of phase amplifiers 14,14,16, the signal in the radiation antenna means is of predetermined level and is confined generally throughout the roadway to the upper vicinity thereof and is attenuated laterally of the roadway to a predetemiined level extending remotely outwardly from the roadway.

Each of the wires A,B1,B2,Cl,C2 is a conductor wire made of copper, or the like, and is of substantial sized conductor measured along its diameter. The conductor wire 12 is encased or wrapped in a low dielectric constant insulation material of substantial thickness, so that there results dissipation and reradiation of radiant energy from the conductor wire itself into the lossy road and ground material adjacent the insulated conductor.

The inner pair of conductor wires B1,B2 provides for the main extension of the wave pattern projecting throughout the immediate upper vicinity of the roadway, and the outer pair of conductor wires C1,C2 provides for constraint to a predetermined level of the pattern of radio communication from extending remotely outwardly of the roadway and to increase the field over the roadway.

As is shown in the drawing, the communications transmitter means 26 has the output terminal thereof conducted to a pair of conductors 60 extending alongside or about the roadway, and may be a coaxial cable or other non-radiating conductor, so that a plurality of connected bridging amplifiers similar to bridging amplifier 22 may be connected in parallel across the conductors 60, and these may be done in sections measured in approximately 1,300-foot lengths, or any convenient length, as shown. Also, there may be provided a line booster or driver 62 for amplification of the signal for increasing the level of the signal being fed to successor bridging amplifiers 22, as desired.

Additional embodiments of the invention in this specification will occur to others and therefore it is intended that the true spirit of the invention be limited only by the appended claims and not by the embodiment described hereinabove. Accordingly, reference should be made to the following claims in determining the true spirit of the invention.

What is claimed is:

1. A roadway radio communication system for transmitting a radio communication signal to vehicles for traveling along the roadway comprising:

a radio communications transmitter means having an input signal coupled thereto from a program signal source and producing an output drive signal coupled therefrom,

a series of bridging amplifiers each coupled to the output drive signal of said radio communications transmitter,

a set of at least two in-phase and one out-of-phase amplifiers being driven by one of said series of bridging amplifiers, said in-phase amplifiers being identified as in-phase with said bridging amplifier and said out-of-phase amplifier being out-of-phase with said bridging amplifier,

a set of five road-imbedded wires generally parallel oriented longitudinally beneath the surface of said roadway constituting radiation antenna means being coupled to a center wire, an inner pair and an outer pair of wires, respectively,

means coupling said center wire to the output terminal of said out-of-phase amplifier,

means coupling said inner pair of wires to the output terminals of said in-phase amplifiers, and

means coupling said outer pair of wires through an impedance means to the output terminals of said out-ofphase amplifier, or to such amplifiers or phase networks as will insure constraint of its signal field,

impedance terminating units at the ends of each of the set of five road-imbedded wires and connected between said ends and electrical ground, and

said set of amplifiers phasing communication signals produced in said inner pair of wires in substantial phase 3. The invention of claim 2 wherein said set of five road-imbedded wires is disposed to a substantially uniform predetermined depth substantially throughout the lengths of the wires beneath the surface of the roadway.

4. The invention of claim 1 wherein said radiation antenna means are in adjacent l,300-foot sections throughout a length of said roadway.

5. The invention of claim 1 wherein a line booster is provided between given section lengths of said radiation antenna means for amplification of the signal for increasing the level of the signal being fed to successor bridging amplifiers. 

1. A roadway radio communication system for transmitting a radio communication signal to vehicles for traveling along the roadway comprising: a radio communications transmitter means having an input signal coupled thereto from a program signal source and producing an output drive signal coupled therefrom, a series of bridging amplifiers each coupled to the output drive signal of said radio communications transmitter, a set of at least two in-phase and one out-of-phase amplifiers being driven by one of said series of bridging amplifiers, said in-phase amplifiers being identified as in-phase with said bridging amplifier and said out-of-phase amplifier being outof-phase with said bridging amplifier, a set of five road-imbedded wires generally parallel oriented longitudinally beneath the surface of said roadway constituting radiation antenna means being coupled to a center wire, an inner pair and an outer pair of wires, respectively, means coupling said center wire to the output terminal of said out-of-phase amplifier, means coupling said inner pair of wires to the output terminals of said in-phase amplifiers, and means coupling said outer pair of wires through an impedance means to the output terminals of said out-of-phase amplifier, or to such amplifiers or phase networks as will insure constraint of its signal field, impedance terminating units at the ends of each of the set of five road-imbedded wires and connected between said ends and electrical ground, and said set of amplifiers phasing communication signals produced in said inner pair of wires in substantial phase opposition to the communication signals in the center wire and outer pair of wires, whereby communication signals of predetermined level are confined to the immediate upper vicinity of the roadway, constrained to a predetermined level remotely outwardly of the roadway.
 2. The invention of claim 1 wherein said set of five road-imbedded wires comprises a substantial sized copper conductor measured along its diameter and said conductor is encased in a low dielectric constant insulation material of substantial thickness.
 3. The invention of claim 2 wherein said set of five road-imbedded wires is disposed to a substantially uniform predetermined depth substantially throughout the lengths of the wires beneath the surface of the roadway.
 4. The invention of claim 1 wherein said radiation antenna means are in adjacent 1,300-foot sections throughout a length of said roadway.
 5. The invention of claim 1 wherein a line booster is provided between given section lengths of said radiation antenna means for amplification of the signal for increasing the level of the signal being fed to successor bridging amplifiers. 